The field of this invention relates to swedges, tubular expansion devices, which can seal an inner pipe to an outer pipe by expansion when the outer pipe is somewhat out of round without need to expand the outer pipe.
In the past, techniques have been developed to expand and inner pipe against an outer pipe and such techniques have been applied to attach a liner to casing in a well bore. Because segments of well bore casing could be out of round prior techniques have required a swedge system to have sufficient power to not only expand the inner tubular but also to expand the outer tubular to insure fixation in a full circumferential manner of the inner tubing against the outer tubing. This technique illustrated in U.S. Pat. No. 6,098,717 required the inner tubular to be expanded beyond the yield point by drawing a swedge through it. The inner tubular expanded sufficiently such that the elastic recovery for the inner tubular was less than the elastic recovery for the outer tubular to insure that the tubulars sealed against each other. While this technique was effective, it required significant amount of pulling force or applied horsepower on the swedge.
However, there are applications where the power available to drive the swedge is limited but the circumstances still call for a reliable sealed connection between the inner tubular and the outer tubular in circumstances where the outer tubular could be somewhat out of round. It is therefore an object of the present invention to be able to accommodate situations where the outer tubular is out of round and expand an inner tubular assembly in such a manner as to fully seal in the portions of the outer tubular which are out of round. It is a further object of the present invention to reduce the required applied force driving the swedge to make a sealed connection between the inner and outer tubulars. Those advantages and others will be readily apparent to those skilled in the art from a review of the description of the preferred embodiment which appears below.
A swedge assembly is disclosed which has the capability of allowing for a sealing connection between an inner tubular and an outer tubular where the outer tubular has significant out of roundness. A resilient segment or segments is disposed on the swedge in contact with the inner tubular to be expanded so as to fill any voids created by out of roundness of the outer tubular. The resilient material may be an elastomer or any pliable metallic or any other material compatible with the applicable well bore conditions.